Electrodeposition of lead sulphide in acidic medium

Polycrystalline thin films of lead sulphide were electrodeposited on titanium, aluminium and stainless steel (SS) substrates at a constant potential of -0.7V vs. Ag\AgCl\(sat)KCl electrode using 1 mM solutions of Pb(NO,), and Na2S2O3 at pH2.7, 2.8 and 2.9. Except at pH 2.9 (which also gave tetragonal PbS2) all other pHs gave single phase PbS (fee). While deposition on Al gave a crystalline phase of PbS with very prominent (200) and (111) planes, that on SS substrate showed growth of the (200) plane only. Although the deposition of PbS on Ti was good, it showed (111) and (200) planes of low intensity compared to that on Al. Film thickness and grain size were found to be of the order of micrometres. The cyclic voltammetry of the film formation was studied in a potential range -1 to OV (Ag\AgCl) followed by XRD, SEM and AFM analyses. The mechanism of growth is discussed. (C) 1997 Elsevier Science S.A